There are a number of devices known in the art, usually called “pigs”, which are adapted to travel through the pipeline with the fluids, such as crude oil, and measure pressure drops in the pipeline to detect leaks therein. Examples of such devices are disclosed in U.S. Pat. Nos. 3,974,680 and 4,020,674. Such pigs are large devices encompassing essentially the entire internal circumferential space within the pipeline, and they normally run only in clean, unrestricted pipelines that transport clear fluids. They would not be suitable for pipelines transporting solids where they would quickly become clogged and inoperative.
Another “intelligent pig” is disclosed in Canadian Patent Application No. 2,218,029 published Apr. 10, 1999, where the body of the pig is surrounded with soft foam and a sensor is connected to said body to measure wax deposits in the pipeline. It requires that the body of the device should at least partially block the flow of fluid within the pipeline. Again, such device takes up essentially the entire circumferential space within the pipeline as it travels and it would not be suitable for paste or slurry pipeline systems where it would be quickly damaged.
There has long been a need for mine operators to better understand flow rheology particular to their backfill systems. A considerable amount of effort and money has been spend to identify and remedy the cause and effect of water-hammer, cascades, impact points, adiabatic heating and the effects of vugs, vacuums, line restrictions and pressure spikes during mining backfill operations. Similar problems arise in other solids transport systems, such as used for concrete piping and the transport of other pastes or slurries. Until now they remained without solution. There is thus a need for a device that would provide in-line measurement of properties of fluids transported by pipelines and especially in solids transport pipeline systems that would allow the operator to quickly calculate friction loss or deduce anomalies in the system.